Electromagnetically shielded roebel coil

Abstract

This utility model relates to an anti-electromagnetic interference Rogowski coil, comprising multiple continuously wound and interconnected hollow coils. Each hollow coil includes continuously wound single coil layers arranged neatly according to wire diameter. The next single coil layer is continuously wound around the outer side of each single coil layer, with adjacent inner and outer single coil layers arranged neatly. The number of single coil layers is odd, and ≥3 layers. The tail end of each hollow coil is connected to the head end of the next hollow coil. This design better maintains the structural and distribution consistency of each hollow coil, and when subjected to external magnetic field interference, it can better and more evenly cancel the generated induced electromotive force, achieving better resistance to external magnetic field interference and improving the accuracy and anti-interference capability of the meter.

Description

Technical Field

[0001] This utility model relates to an anti-electromagnetic interference Rogowski coil for use in power instruments, and particularly to an anti-electromagnetic interference Rogowski coil suitable for the field of power transmission. Background Technology

[0002] In the development of smart grids in China, electronic instrument transformers are a key component of primary equipment. Currently, current transformers are the primary method used for AC current detection.

[0003] There are two main types of current transformers. One type is the iron core coil transformer, which is made in different sizes according to the rated current. Its disadvantages are that it is large in size and high in cost. It is used in iron cores and has magnetic saturation phenomenon and nonlinearity. Therefore, its current measurement range is narrow and it is commonly used for 0.1In to 2In (rated current).

[0004] Another type is the Rogowski coil current sensor. Also known as an air-core transformer or magnetic potential gauge, the Rogowski coil is widely used for measuring large currents. A Rogowski coil is a coil uniformly wound around a non-magnetic frame, surrounding a conductor, and is used to measure the current flowing through the conductor. A Rogowski coil current sensor consists of two main parts: the Rogowski coil sensing head and the subsequent signal integration and processing circuitry. The sensing head is the signal sensing element of the measuring element; it establishes a coupling relationship with the measured current by capturing the electromagnetic field in space. Rogowski coils are characterized by their small size and low material cost, excellent linearity, and wide measurement range, suitable for currents from 0.1 In to tens of thousands of A or even higher. However, they are particularly susceptible to electromagnetic interference, especially power frequency electromagnetic fields. They are typically used for detecting large currents, such as AC currents of several hundred amperes or more. When used for small currents, they are highly susceptible to interference from external power frequency electromagnetic fields. This causes the sampling current output by the Rogowski coil to include not only the measuring current flowing in the measured conductor but also interference signal current generated by the surrounding electromagnetic field. When the measuring current is small, the interference signal current may even cover the measuring current, leading to a large measurement error and failing to accurately reflect the actual current, thus creating certain limitations.

[0005] Therefore, in the power sector, especially under the stringent requirements related to the safety of electricity use for the general public, how to optimize instrument transformers to improve their ability to resist external magnetic field interference is an urgent problem that needs to be studied and solved by those skilled in the art. Utility Model Content

[0006] The purpose of this invention is to provide an electromagnetic interference resistant Rogowski coil that is resistant to external magnetic field interference and is easy to manufacture and assemble.

[0007] To achieve the above technical objectives, this utility model adopts the following technical approach:

[0008] An electromagnetic interference resistant Rogowski coil is characterized by comprising a plurality of continuously wound and interconnected hollow coils, each hollow coil comprising a continuously wound single coil layer arranged neatly according to wire diameter, each single coil layer having a next single coil layer continuously wound around its outer side, adjacent inner and outer single coil layers arranged neatly, the number of single coil layers being odd and ≥3 layers; the tail end of each hollow coil is connected to the head end of the next hollow coil.

[0009] As a further improvement of this utility model, the wire diameter and number of turns of each single coil layer in the hollow coil are consistent.

[0010] As a further improvement of this utility model, the wire diameter, number of turns, number of layers, inner diameter, and outer diameter of each hollow coil are consistent.

[0011] As a further improvement of this utility model, the hollow coils are an even number of no less than four, and are symmetrically distributed around a circle on the same horizontal plane.

[0012] As a further improvement of this utility model, multiple hollow coils are continuously wound from a single enameled wire.

[0013] As a further improvement of this utility model, the enameled wire is a self-adhesive enameled wire.

[0014] As a further improvement of this utility model, the multiple hollow coils of the anti-electromagnetic interference Rogowski coil are arranged in a stepped manner and wound one by one.

[0015] As a further improvement of this utility model, the end of the hollow coil is further wound with a canceling coil or further connected to a circuit board containing a canceling circuit.

[0016] As a further improvement of this utility model, the canceling coil or canceling circuit is wound in a circular shape from the inside to the outside.

[0017] As a further improvement of this utility model, the reclamation area of ​​the offset coil or offset circuit is equal to the reclamation area enclosed by the plurality of hollow coils.

[0018] Compared to existing technologies, this utility model's coreless coil assembly eliminates the need for a core. It comprises multiple interconnected hollow coils continuously wound from a single enameled wire. Each hollow coil has multiple inner and outer layers, with adjacent single coils arranged neatly according to wire diameter without overlap. This facilitates control over the wire diameter, number of layers, number of turns, inner diameter, and outer diameter of each hollow coil. Adjacent single hollow coils are connected end-to-end, with the ends of the enameled wire extending to form the output terminals of the coreless coil assembly, creating an electromagnetic interference-resistant Rogowski coil. This design avoids issues such as induced saturation under external magnetic field interference and DC electromagnetic interference. The coreless coil assembly better maintains the structural and distribution consistency of each hollow coil. When an even number of axially symmetrically distributed hollow coils are subjected to external magnetic field interference, the generated induced electromotive force can be better and more evenly canceled, achieving better resistance to external magnetic field interference and improving the accuracy and anti-interference capability of the meter. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the first coil of the anti-electromagnetic interference Rogowski coil of this utility model;

[0020] Figure 2 yes Figure 1 A structural diagram from another angle;

[0021] Figure 3 This is a side view of the first coil of the Rogowski coil for electromagnetic interference suppression of this utility model;

[0022] Figure 4 This is a schematic diagram of the structure of the anti-electromagnetic interference Rogowski coil of this utility model, in which the first and second coils are wound in a stepped arrangement;

[0023] Figure 5 This is a schematic diagram of the structure of the anti-electromagnetic interference Rogowski coil of this utility model, in which the first to sixth coils are arranged in a stepped manner and wound one by one.

[0024] Figure 6 This is a schematic diagram of the coreless coil assembly structure of the Rogowski coil after bending, which is an anti-electromagnetic interference device of this utility model.

[0025] Figure 7 yes Figure 6 A schematic diagram of a coreless coil assembly structure from another angle;

[0026] Figure 8 This is a schematic diagram of the coreless coil group structure of the second embodiment of the anti-electromagnetic interference Rogowski coil of this utility model, which is arranged in a stepped manner and wound one by one.

[0027] Figure 9 yes Figure 8 A schematic diagram of a coreless coil assembly structure from another angle;

[0028] Figure 10 yes Figure 8 A schematic diagram of a coreless coil assembly structure at another angle;

[0029] Figure 11 This is a schematic diagram of the coreless coil assembly structure after bending and positioning in the second embodiment of the anti-electromagnetic interference Rogowski coil of this utility model.

[0030] Figure 12 This is an exploded view of the coreless coil group structure of the third embodiment of the anti-electromagnetic interference Rogowski coil of this utility model;

[0031] Figure 13 This is a schematic diagram of the coreless coil group structure of the third embodiment of the anti-electromagnetic interference Rogowski coil of this utility model.

[0032] Figure label:

[0033] Rogowski coils with electromagnetic interference suppression: 100, 200, 300

[0034] Enameled wire 1, head 11

[0035] Tail end 12 coreless coil group 2

[0036] Hollow coil 20, head end 221

[0037] Tail end 222 First coil 21

[0038] Second coil 22, Third coil 23

[0039] Fourth coil 24, Fifth coil 25

[0040] Sixth coil 26, single coil layer 2210

[0041] First coil layer 2211 Second coil layer 2212

[0042] Third coil layer 2213 canceling coil 3

[0043] Cancellation Line 4 Circuit Board 40

[0044] Output terminals 5, 5', 5" Detailed Implementation

[0045] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0046] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0047] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0048] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0049] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0050] Please refer to Figures 1 to 7 The diagram shown is a structural schematic of the anti-electromagnetic interference Rogowski coil 100 according to the first embodiment of this utility model. The anti-electromagnetic interference Rogowski coil 100 can be manufactured by the following winding method:

[0051] Multiple hollow coils 20 are continuously wound and interconnected from a single enameled wire 1. Each hollow coil 20 is hollow inside. Each hollow coil 20 comprises a single coil layer 2210 continuously wound on a coil jig (not shown) and arranged neatly according to wire diameter. Figure 2 As shown, the innermost layer is the first coil layer 2211, which is formed by winding several parallel single-strand coils of the same circumference on a coil fixture similar to a cylinder (the cross-section can be circular, racetrack-shaped, square, etc.) from the head 11 of a single enameled wire 1. These parallel single-strand coils form the first coil layer 2211. After each single-strand coil layer 2210 is wound, the next single-strand coil layer 2210 is wound in the opposite direction on the outside. For example, after the first coil layer 2211 is wound, the tail 12 of the enameled wire 1 immediately begins winding the second coil layer 2212 outside the first coil layer 2211. Figure 2 For example, the first coil layer 2211 is wound from left to right, the second coil layer 2212 is wound from right to left, the third coil layer 2213 is wound from left to right again, and so on. The adjacent inner and outer single coil layers 2210 are arranged neatly, which can improve the structural consistency of each hollow coil 20 and improve the arrangement accuracy. The number of single coil layers 2210 is odd and ≥3 layers. Figure 3As shown, the number of the single coil layers 2210 can be 7 layers, which can make the head end 221 and the tail end 222 of a single hollow coil 20 be located on both sides of its main body respectively, facilitating the winding of the next single hollow coil 20. No core body such as an iron core needs to be placed inside the hollow coil 20. In this way, the electromagnetic interference-resistant Rogowski coil 100 has no magnetic saturation, making it extremely suitable for measuring very large currents, currents containing DC components (such as short-circuit fault currents, currents in power electronic devices), and severely distorted currents; wide frequency response, without the limitations of eddy current loss, hysteresis loss, and distributed capacitance brought by the iron core, having a very wide bandwidth (from a few Hz to several MHz, or even higher), enabling it to accurately measure high-frequency currents, fast transient currents (such as lightning strikes, switching operation surges, fast turn-off currents of power electronic switches), and currents containing rich harmonics; good linearity, the output signal (induced voltage) is strictly proportional to the change rate (di / dt) of the measured current. When the coil design parameters (such as turn density, cross-sectional area) remain unchanged and there is no saturation, its response is linear, making it maintain a good linear relationship between the input (current change rate) and the output (voltage) within the entire measurement range, with high measurement accuracy; low load effect, the output impedance is relatively low, and the load effect on the measured circuit is very small, hardly affecting the measured current loop, making it convenient to access the measurement system; flexible, lightweight, and easy to install, facilitating installation in places with limited space. The coil itself has good electrical isolation from the measured high-voltage conductor, improving the operation safety; wide measurement range, by adjusting the coil turns and other device parameters, the same coil design can cover a very wide current measurement range (from a few amperes to millions of amperes), without the need for different transformation ratios like traditional CTs; no residual magnetism, no residual magnetism will be left after measurement, not affecting the accuracy of the next measurement, especially suitable for measuring non-periodic transient large currents.

[0052] On the next coil fixture that is vertically and horizontally misaligned with the above-mentioned coil fixture, continuously wind the next hollow coil 20 to Figure 4 take... as an example. In the illustration, the positional relationship between the adjacent two coil fixtures (not shown) is vertical and horizontal misalignment. In this way, the winding of the second coil 22 will not be hindered after the winding of the first coil 21 is completed, that is, the winding processes of the first coil 21 and the first coil 21 do not affect each other, improving the automation production efficiency.

[0053] Refer to Figure 5As shown, in different embodiments, multiple coil fixtures are arranged in a stepped manner in sequence. For example, the positional relationship between two adjacent coil fixtures (not shown) is offset vertically and horizontally, forming a stepped shape. That is, after the first coil is wound on the first coil fixture, the second coil fixture automatically extends or is placed to continuously wind the second coil, and the winding is sequentially continued to the last coil. Thus, after multiple hollow coils 20 are wound on multiple coil fixtures, they can be smoothly removed from the coil fixtures to complete automated production. That is, in the figure, the first coil 21, the second coil 22, the third coil 23, the fourth coil 24, the fifth coil 25, and the sixth coil 26 are distributed in a stepped manner from top to bottom and from left to right. With such a setting, it can be ensured that each hollow coil 20 is strictly controlled during the winding process, and the structure and distribution consistency of each hollow coil 20 can be better maintained. When a number of hollow coils 20 are reasonably arranged, for example, when an even number of hollow coils 20 are symmetrically distributed about the axis to form a coreless coil group 2, a primary current line can pass through the axis to detect the power data of the primary current line. When affected by an external magnetic field interference, the induced electromotive force generated can be better and more evenly cancelled, achieving better anti-external magnetic field interference ability and improving the detection accuracy and anti-interference ability of the electric meter.

[0054] Specifically, the wire diameter and number of turns of each single coil layer 2210 in the hollow coil 20 are the same. With such a setting, the structure of each single coil layer 2210 can be made consistent, so that the structure of the entire hollow coil 20 is neat and controllable and has consistency, which is more conducive to maintaining the structure and distribution consistency of each hollow coil 20.

[0055] In a preferred embodiment, the wire diameter, number of turns, number of layers, inner diameter, and outer diameter of each hollow coil 20 are the same. With such a setting, the structure of each hollow coil 20 is consistent, which can avoid manufacturing deviations in geometric structures, such as uneven turn density and irregular cross-sections, and is beneficial to the mutual cancellation of external electromagnetic interference between hollow coils 20.

[0056] Refer Figure 6 and Figure 7 As shown, the hollow coils 20 are an even number not less than 4 and are symmetrically distributed about a circle on the same horizontal plane. With such a setting, 4 or more hollow coils 20 can evenly cancel external magnetic field interference in four or more directions respectively, improving the accuracy of anti-external magnetic field interference.

[0057] According to the different shapes of the coil fixtures, the cross-section of each single coil layer 2210 can be circular, racetrack-shaped, or rectangular. Thus, it is convenient for the winding of the hollow coil 20. Figure 6 For example, the cross-section of each single coil layer 2210 is circular.

[0058] Reference Figure 6 、 7 As shown, the enameled wire 1 is provided with a head 11 and a tail 12, which can serve as the output terminal 5 of the electromagnetic interference-resistant Rogowski coil 100. With this arrangement, after an even number of hollow coils 20 distributed symmetrically about the axis form a coreless coil group 2, the primary current wire can pass through the axis, for detecting the power data of the primary current wire and transmitting the power data outward through the output terminal 5.

[0059] In a preferred embodiment, the enameled wire 1 is a self-adhesive enameled wire 1. That is, the outer side of the enameled wire 1 has a certain viscosity. During the winding process of the hollow coil 20, the enameled wire 1 can adhere to and locate with the adjacent part of the enameled wire 1 while winding, which can greatly facilitate the winding and fixing of the enameled wire 1. In other embodiments of the present invention, the self-adhesive enameled wire 1 can also be formed by coating adhesives or other methods to increase the mutual viscosity, which is also within the protection scope of the present invention.

[0060] As a preferred embodiment of the present invention, the end of the hollow coil 20 is further wound with a cancellation coil 3 or further connected to a circuit board 40 containing a cancellation circuit 4.

[0061] Reference Figures 8 to 11 As shown, it is the electromagnetic interference-resistant Rogowski coil 200 of the second embodiment of the present invention. That is, the end of the hollow coil 20 is further wound with a cancellation coil 3. With this arrangement, after multiple hollow coils 20 are symmetrically distributed about a circle on the same horizontal plane to form a coreless coil group 2, the center of the cancellation coil 3 can coincide with the center of the coreless coil group 2 for the primary current wire to pass through. The cancellation coil 3 can just be located on one side of the coreless coil group 2 and be parallel to the same horizontal plane symmetrically distributed about the circle. When the coreless coil group 2 detects the power data of the primary current wire, the output terminal 5' outputs the power data outward. The responses of the coreless coil group 2 and the cancellation coil 3 to the measured primary current wire are in the same phase (additive), but the responses to the external vertical magnetic field interference are in the opposite phase (subtractive). This can help eliminate or resist the interference of the vertical alternating magnetic field received.

[0062] Reference Figure 12 、 Figure 13 As shown, it is the electromagnetic interference-resistant Rogowski coil 300 of the third embodiment of the present invention. The differences from the electromagnetic interference-resistant Rogowski coil 200 of the second embodiment include: a cancellation circuit 4 similar to the cancellation coil 3 is built into the circuit board 40, and the output terminal 5'' outputs the power data outward. With this arrangement, the structural neatness of the cancellation circuit 4 can be further fixed. When it is necessary to package and fix the coreless coil group 2 and the cancellation circuit 4, the positional relationship between the two can be better positioned, avoiding installation and positioning deviations of the geometric structure.

[0063] Reference Figure 9 and 12 As shown in Figure 9 and 12 , in a preferred embodiment, the cancellation coil 3 or the cancellation line 4 is wound in a circular ring shape from the inside out. Such a setting is beneficial to determining and setting the reclamation area parameters of the cancellation coil 3 or the cancellation line 4, and is convenient for manufacturing and forming.

[0064] As a preferred embodiment of the present invention, the reclamation area of the cancellation coil 3 or the cancellation line 4 is equal to the reclamation area surrounded by the plurality of hollow coils 20. Such a setting enables the cancellation coil 3 or the cancellation line 4 to better eliminate or resist the interference of the vertically alternating magnetic field when the coreless coil group 2 detects the power data of the primary current line, so that the electromagnetic interference-resistant Rogowski coil 100 can better cancel the external magnetic field interference in all directions, achieving the anti-interference performance and accuracy of power detection.

[0065] The electromagnetic interference-resistant Rogowski coil 100 of the present invention includes a plurality of hollow coils 20 that are continuously wound and connected to each other. Each single hollow coil 20 includes a single coil layer 2210 that is continuously wound and arranged neatly according to wire diameters. A next single coil layer 2210 is continuously wound and turned outside each single coil layer 2210. The adjacent inner and outer single coil layers 2210 are arranged neatly. The number of the single coil layers 2210 is odd and ≥ 3. The tail end 222 of each single hollow coil 20 is connected to the head end 221 of the next hollow coil 20. Such a setting makes each single hollow coil 20 composed of a plurality of single coil layers 2210 stacked neatly from the inside out, hollow inside, and the head end 221 and the tail end 222 are located on both sides respectively, enabling the plurality of continuously wound hollow coils 20 to be connected in series, which is beneficial to arranging them in a form such as symmetrically distributed around a circle on the same horizontal plane or other arrangement forms. Thus, when detecting the power data of the primary current line outside the primary current line, it can better and more evenly cancel the induced electromotive force generated by each due to external magnetic field interference, achieving better anti-external magnetic field interference ability and improving the detection accuracy and anti-interference performance of the electric meter.

[0066] Preferably, the plurality of hollow coils 20 are continuously wound from a single enameled wire 1. In this way, it is convenient for manufacturing and is beneficial to the overall strength and electrical parameter uniformity of the electromagnetic interference-resistant Rogowski coil 100.

[0067] Reference Figure 5 As shown, the plurality of hollow coils 20 of the electromagnetic interference-resistant Rogowski coil 100 are arranged in a stepped manner and continuously wound one by one. In this way, continuous winding production can be carried out on a stepped winding jig, which is convenient for manufacturing and improves the automated production efficiency. Of course, in other embodiments of the present invention, due to the flexibility of the enameled wire 1, arranging the plurality of hollow coils 20 in a linear distribution or other regular or irregular forms of distribution is within the protection scope of the present invention.

[0068] The cancelling coil 3 further wound around the end of the hollow coil 20 of the anti-electromagnetic interference Rogowski coils 200 and 300, or the circuit board 40 further connected to it containing the cancelling circuit 4, are all within the protection scope of this utility model, regardless of their arrangement, due to the flexibility of the enameled wire 1. The enclosed area of ​​the cancelling coil 3 or the cancelling circuit 4 is equal to the enclosed area of ​​the plurality of hollow coils 20.

[0069] The cancelling coil 3 or cancelling line 4 is wound in a circular shape from the inside out. In other embodiments of this utility model, the cancelling coil 3 or cancelling line 4 may also be wound in other ways, all of which are within the protection scope of this utility model.

[0070] It is worth noting that in this utility model, the order of the above steps is not limited and can be adjusted according to the actual situation, all of which are within the protection scope of this utility model.

[0071] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0072] The directional terms used in the various technical features described in the above embodiments, such as front, back, left, right, up, and down, are used only for the convenience of describing and understanding the various technical features, and do not constitute a limitation on specific directions in the actual use of the technical solution.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. An electromagnetic interference resistant Rogowski coil, characterized by: It includes multiple hollow coils that are continuously wound and interconnected. Each hollow coil includes a single coil layer that is continuously wound and arranged neatly according to wire diameter. The next single coil layer is continuously wound around the outside of each single coil layer. The adjacent inner and outer single coil layers are arranged neatly. The number of single coil layers is odd and ≥3 layers. The tail end of each hollow coil is connected to the head end of the next hollow coil.

2. The electromagnetic interference resistant Rogowski coil of claim 1, wherein: The wire diameter and number of turns are consistent in each single coil layer within the hollow coil.

3. The electromagnetic interference resistant Rogowski coil of claim 1, wherein: The wire diameter, number of turns, number of layers, inner diameter, and outer diameter of each hollow coil are consistent.

4. The electromagnetic interference resistant Rogowski coil of claim 1, wherein: The hollow coils are an even number of no fewer than four, and are symmetrically distributed around a circle on the same horizontal plane.

5. The electromagnetic interference resistant Rogowski coil of claim 1, wherein: The multiple hollow coils are continuously wound from a single enameled wire.

6. The electromagnetic interference resistant Rogowski coil of claim 1, wherein: The enameled wire is a self-adhesive enameled wire.

7. The electromagnetic interference resistant Rogowski coil of claim 1, wherein: The multiple hollow coils of the electromagnetic interference-resistant Rogowski coil are arranged in a stepped manner and wound one by one.

8. The electromagnetic interference resistant Rogowski coil of claim 1, wherein: The hollow coil is further wound with a canceling coil at its end or further connected to a circuit board containing a canceling circuit.

9. An electromagnetic interference resistant Rogowski coil according to claim 8, wherein: The cancelling coil or cancelling circuit is wound in a circular shape from the inside out.

10. The Rogowski coil for electromagnetic interference suppression according to claim 8, characterized in that: The reclamation area of ​​the offset coil or offset line is equal to the reclamation area enclosed by the plurality of hollow coils.

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